There is a need to stack individual printed sheet-like articles such as tickets, labels, cards and the like after they are fed from a printer. For instance, a label printing machine can print labels and cut them into individual labels which are then dispensed in series from the printer at speeds up to about 240 labels per minute. It is desirable to stack such printed articles continuously so that the printer need not be stopped or delayed during its high speed printing operation.
It is also often desirable to stack printed articles of varying length. For instance, a computer-controlled machine for printing tickets may print groups of tickets in different formats and separate the groups by flag cards which are longer than the tickets being printed. There is a need for a stacking machine that can stack such tickets on-end with the groups of tickets being separated by the longer flag cards, without the different lengths of tickets and flag cards interfering with the continuous stacking operation or delaying the printer.
A stacking machine also should be able to stack articles at high speed independently of any random spacing between the articles fed in series to the stacking machine from a printer or the like.
Moreover, a stacking machine that operates at high speed must be able to push articles onto a stack and prevent the stacked articles from backing up and interferring with the continuous operation of the stacking machine. A high speed stacking machine must be especially reliable in stacking flexible articles such as tickets which can be prone to buckling, bending, or possibly snagging the stacking mechanism.
The present invention solves these problems by providing a high speed stacking machine that continuously stacks individual articles fed in series to the stacker, independently of variations in the length of the stacked articles and independently of any random spacing between the articles being fed to the stacker. The stacking machine also stacks articles rapidly while preventing the stacked articles or bendable articles from interferring with the rapid cycling of the stacker.